A major challenge to the medical sciences is understanding the mechanisms of, and development of treatments for, the large group of disorders that are primarily genetic in origin. The techniques of molecular biology have made it possible to identify and characterize defective genes and proteins, and to potentially treat disease by gene replacement therapy, but wide gaps in knowledge of the cellular and molecular mechanisms of pathogenesis remain. Because of their broad education in the biological medical sciences and their direct involvement in the health and productivity of animals, veterinarians are ideally suited to play major roles in research into the basic mechanism involved in genetic diseases, gene therapy, and in the identification and engineering of genes that will be important in producing disease resistant livestock. The University of Pennsylvania School of Veterinary Medicine has established an extensive research program aimed at understanding the molecular pathogenesis and treatment of genetic diseases by utilizing animal models of human genetic disease. It is the only veterinary school in the United States with a formal academic subdivision devoted primarily to the identification and study of genetic diseases of domestic animals, and has been an NCRR-supported National Refemil Center for Animal Models of Human Genetic Disease since 1985. Studies on individual animal models that can address important scientific questions concerning mechanisms and treatments are support by a large number of NIH and private foundation grants to investigators in the Veterinary School and other biomedical institutions on the campus. This grant proposes to attract and train talented veterinary scientists in genetics research, emphasizing those fields which provide the greatest potential to advance the understanding, treatment, and prevention of diseases in which genes play a major role. This proposal is the outgrowth of a pilot program, supported by a one-time grant from a private foundation, to support post-doctoral training in veterinary medical and molecular genetics. All of the trainees who have completed the program have obtained faculty positions at research universities. We expect the program to produce a cadre of outstanding young scientists who will not only advance knowledge, but who will, through their influence on the profession and related fields, serve as leaders in the further development of medical genetics in veterinary medicine. Increasing the number of comparative medical scientists with solid training in molecular biology at this time will result in increased availability to the biomedical research community of animal models of human genetic diseases that are characterized in sufficient depth to allow studies that will advance general understanding of genetic diseases and their treatments.